Modifiable risk factors in colorectal surgery: central role of surgeon's volume.

Background: Our objective was to inform the ongoing debate regarding selective referral of colorectal cancer patients to high-volume surgeons in order to improve outcomes.

Patients And Method: We evaluated data on patients treated by colorectal-dedicated surgeons (first study-group) and non specialized surgeons (second study-group). Particular attention has been paid to patients selection in order to collect two study-groups with similar demographic and clinical characteristics, differing only as regards providers' surgical experience in the colorectal field. We focused on postoperative mortality and 5-year overall and cancer-specific survival. We also analyzed resection rates of the primary tumor and colostomy rates for patients with stage I to III rectal cancer, and use of (neo)adjuvant (chemo)radiation therapy for patients with stage II-III rectal cancer by surgeon's volume.

Results: The analysis of these 2 study-groups shows better results for patients treated by colorectal-trained surgeons (high-volume surgeons) for each parameter taken into account: lower postoperative mortality (OR 0.32; 95% CI:0.7-0.1; p = 0.04), increased 5-year overall and cancer specific survival (rising from 41.2% and 46.4% to 56% and 61.2% respectively; OR 1.8; 95% CI: 1.3-2.6; p < 0.005). Patient treated by non specialized surgeons are more likely to receive a permanent colostomy (abdominoperineal resection: APR) (OR 5.9; 95% CI: 3.3-10.7) and to undergo a non-resective procedure (OR 4.8; 95% CI: 1.9-12)(p < 0.005). No difference was found between the 2 study-groups in the use of (neo)adjuvant (chemo)radiation therapy for patients with stage II-III rectal cancer.

Conclusions: Our analysis suggests that surgeon's volume does impact on outcomes for patients undergoing surgery due to colorectal cancer.